JP2013138193A - Heat sink and electronic component device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink which improves heat radiation characteristics of individual fins thereby improving overall heat radiation characteristics, and to provide an electronic component device using the heat sink.SOLUTION: A heat sink includes: a substrate 1 on which a heating member is placed; and multiple columnar fins 2 joined to a surface of the substrate 1 which is opposite to the surface on which the heating member is placed and disposed at intervals. Each fin 2 has at least one of a recessed part 2a and a protruding part 2b at portions that face the adjacent fins 2. In the heat sink, surface areas of the fins, which enable heat radiation, are increased and thus heat radiation characteristics are improved.

Description

  The present invention relates to a heat sink for dissipating heat generated in a heat generating member and an electronic component device including the heat sink.

  In recent years, insulated gate bipolar transistor (IGBT) devices, metal oxide field effect transistor (MOSFET) devices, light emitting diode (LED) devices, freewheeling diode (FWD) devices, giant transistor (GTR) devices, etc. An electronic device in which various electronic components such as a semiconductor element, a sublimation type thermal printer head element, a thermal ink jet printer head element, and a Peltier element are mounted on a circuit member of a circuit board is used.

  A circuit board provided with a circuit member for mounting such electronic components is, for example, a support substrate made of an insulating ceramic sintered body, and a circuit member mainly composed of copper is supported on one main surface. A heat radiating member, which is a heat sink having a plurality of fins, is joined to the other main surface via the substrate.

  As such a heat sink, for example, Patent Document 1 exemplifies a heat dissipation structure including planar fins.

International Publication No. 2000/0776940 Pamphlet

  By the way, particularly in recent years, with the miniaturization of electronic components, there has been a demand for a heat sink capable of efficiently cooling the electronic components and an electronic component device including the heat sink.

  Therefore, an object of the present invention is to provide a heat sink with improved heat dissipation characteristics and an electronic component device including the heat sink.

  The heat sink of the present invention is a columnar fin that is bonded to a base on which a heat generating member is placed and a surface of the base opposite to the surface on which the heat generating member is placed, and a plurality of them are arranged at intervals. The fin has at least one of a concave portion and a convex portion at a portion facing the adjacent fin.

  The electronic component device of the present invention is characterized in that an electronic component is mounted on the heat sink having the above-described configuration.

  The heat sink of the present invention is a columnar fin that is bonded to a base on which a heat generating member is placed and a surface of the base opposite to the surface on which the heat generating member is placed, and a plurality of them are arranged at intervals. Since the fin has at least one of the concave portion and the convex portion at a portion facing the adjacent fin, the surface area of the fin that can dissipate heat is increased, so that the heat radiation characteristics can be improved.

  Moreover, according to the electronic component device of the present invention, since the electronic component is mounted on the heat sink of the present invention, the heat dissipation characteristics can be improved and the reliability can be improved.

An example of the heat sink of this embodiment is shown, (a) is a schematic perspective view, (b) is an enlarged sectional view taken along the line AA ′ in FIG. (A), and (c) is the same figure. It is the elements on larger scale of the B section of (b). It is an expanded sectional view which shows the other example in the A-A 'line | wire of the figure (a) of the heat sink of the example shown in FIG. It is an expanded sectional view which shows the further another example in the A-A 'line | wire of the figure (a) of the heat sink of the example shown in FIG. It is the elements on larger scale which show the other example of the B section of the heat sink of the example shown in FIG.1 (b). It is an expanded sectional view which shows the other example in the A-A 'line | wire of the heat sink shown to Fig.1 (a). It is the elements on larger scale which show the other example of the junction part of the example shown in FIG. FIG. 6 is an enlarged cross-sectional view showing still another example of the heat sink of FIG. 5 along the line D-D ′. It is a schematic sectional drawing which shows an example of the electronic component apparatus which mounted the electronic component in the heat sink of this embodiment. It is a top view which shows the example of the ceramic green sheet used as the fin which comprises the heat sink of this embodiment. (A) which shows the other example of the ceramic green sheet used as the junction part of FIG. 5 which comprises the heat sink of this embodiment is a top view, (b) is the cross section in the EE 'line of the same figure (a). FIG. (A) which shows the other example of the ceramic green sheet which becomes the junction part of FIG. 5 which comprises the heat sink of this embodiment is a top view, (b) is the cross section in the FF 'line | wire of the same figure (a). FIG.

  Hereinafter, examples of embodiments of the heat sink of the present invention will be described.

  1A and 1B show an example of a heat sink according to the present embodiment. FIG. 1A is a schematic perspective view, FIG. 1B is an enlarged cross-sectional view taken along line AA ′, and FIG. 2) is a partially enlarged view of part B, and FIGS. 2 and 3 are enlarged sectional views showing another example of the heat sink of FIG. 1 along the line AA ′.

  As shown in FIG. 1, the heat sink 10 of this embodiment is joined to a base 1 on which a heat generating member (not shown) is placed, and a surface opposite to the surface on which the heat generating member of the base 1 is placed, A plurality of columnar fins 2 arranged at intervals are provided, and the fin 2 has at least one of the concave portion 2a and the convex portion 2b at a portion facing the adjacent fin 2. In addition, in the base | substrate 1 shown in FIG. 1, the lower surface in FIG. 1A becomes a surface in which a heat radiating member is mounted.

  As shown in FIGS. 1 to 3, the heat sinks 10, 11, and 12 of the present embodiment have fins 2 having at least one of a concave portion 2 a and a convex portion 2 b at a portion facing the adjacent fin 2. The surface area that can dissipate heat 2 increases. Therefore, the heat dissipation characteristics of the heat sink 10 can be improved.

Here, the lengths in the X direction, the Y direction, and the Z direction of the base 1 constituting the heat sinks 10, 11, and 12 of the example shown in FIGS. 1 to 3 are, for example, 15 mm to 75 mm in the X direction, 15 mm or more and 75 mm or less, and Z direction is 7 mm or more and 15 mm or less.

  Moreover, the width | variety of the fin 2 and the space | interval of the adjacent fin 2 are 1 mm or more and 3 mm or less, respectively, and 0.5 mm or more and 2 mm or less, respectively.

  Furthermore, the depth d of the concave portion 2a and the height h of the convex portion 2b are, for example, 0.05 mm or more and 0.5 mm or less, respectively.

  Here, in the heat sink 10 shown in FIG. 1, each fin 2 is provided with a concave portion 2a and a convex portion 2b in order in the columnar vertical direction, and in the heat sink 11 shown in FIG. The concave portion 2a is repeatedly provided on one side, and the convex portion 2b is repeatedly provided on one side of the fin 2 in the heat sink 12 shown in FIG. As described above, by providing at least one of the concave portion 2a and the convex portion 2b in one fin as appropriate, the heat radiation surface area of the fin 2 can be increased. Can be improved. In addition, the number of the recessed parts 2a and the convex parts 2b can be set suitably.

  Here, it is preferable that the fin 2 which comprises the heat sink of this embodiment is a laminated body provided with two or more plate-shaped bodies.

  By reducing the thickness of the plate-like body and deepening the concave portion 2a or increasing the convex portion 2b, the heat dissipating surface area of the fin 2 can be easily increased. The characteristics can be easily improved.

  Here, the fin 2 can be provided with at least one of the concave portion 2a and the convex portion 2b by appropriately shaving the fin 2 or joining a convex member. In the case of a configuration including a plurality of laminated bodies, for example, as in the heat sink 10 shown in FIG. 1, the fin 2 has a configuration in which the concave portion 2 a and the convex portion 2 b are repeatedly provided in the columnar vertical direction. In this case, the plate-like bodies may be laminated while being shifted in order, and in the heat sink 11 shown in FIG. 2 or the heat sink 12 shown in FIG. 3, the plate-like bodies having different sizes may be laminated with the positions on one side aligned. Good.

  In particular, it is preferable that the concave portion 2 a and the convex portion 2 b are provided from one end to the other end in a direction perpendicular to the height direction of the columnar fin 2. Thereby, the surface area of the fin 2 can be further increased, and the heat dissipation characteristics can be further improved. In the case where the fin 2 is constituted by a laminated body including a plurality of plate-like bodies, the concave portions 2a and the convex portions are obtained by laminating each plate-like body with the same size in the direction perpendicular to the laminating direction. It is possible to easily manufacture the fin 2 in which at least one of the 2b is provided from one end to the other end in the direction perpendicular to the height direction of the columnar fins 2 in the direction perpendicular to the stacking direction of the plate-like bodies. . Note that “from one end to the other end” here refers to the X direction shown in FIG. 1.

In addition, such a plate-like body can be easily formed by a doctor blade method, a dry pressure molding method or a powder rolling method, and the thickness thereof becomes, for example, 0.6 mm or more and 2 mm or less. It is preferable that

  In addition, the plate-like body constituting the fin 2 may be formed by stacking, for example, 6 to 12 layers of plate-like bodies in order to make the heat sink have a desired size while maintaining the strength of the fin 2.

  In addition to the fins 2, the substrate 1 may also be configured as a laminate including a plurality of plate-like bodies. In this case, the plate-like bodies having the above thickness may be laminated in two or more layers and four or less layers.

  FIG. 4 is a partially enlarged view showing another example of the B portion of the heat sink of the example shown in FIG.

  As shown in FIG. 4, in the case where the convex portion 2 b is provided in a portion facing the adjacent fin 2, the corner portion 2 c formed by the convex portion 2 b is preferably rounded, The medium between the adjacent fins 2 flows more smoothly in the height direction of the fins 2 (the Z direction shown in FIG. 1) than when the corners of the convex portions 2b are present. Thereby, since it can suppress that the medium with heat retains, since the heat exchange efficiency of a medium and the fin 2 improves, the thermal radiation characteristic of a heat sink can be improved.

  FIG. 5 is an enlarged cross-sectional view showing still another example of the heat sink shown in FIG.

  As shown in FIG. 5, a part of adjacent fins 2 are connected via a joint 2 d, and the joint 2 d is curved in the height direction of the fin 2 between the adjacent fins 2. preferable. Here, when the joint portion 2d is curved upward, the surface area capable of radiating heat can be increased, and the medium flowing upward from below the fin 2 can easily generate a vortex, and the joint portion 2d. In addition, heat exchange can be efficiently performed through the fins 2 in the vicinity of the joint 2d.

  On the other hand, when the joint portion 2d is curved downward, the surface area capable of radiating heat can be increased, and the medium flowing upward from below the fin 2 flows along the curvature. In the case of providing 2d, it is possible to suppress the flow of the medium from being hindered, and the medium can more easily come into contact with the fins 2, so that heat exchange can be performed efficiently.

  FIG. 6 is a partially enlarged view showing another example of the joint 2d in the example shown in FIG.

  As shown in FIG. 6, the surface of the joint 2d having at least one of the concave 2e and the convex 2f can further increase the surface area of the fin 2 that can dissipate heat, thereby further improving the heat dissipation characteristics of the heat sink 13. can do.

  Here, the concave portions 2e and convex portions 2f on the surface of the joint portion 2d shown in FIG. 6 are formed by providing a hole shape on the surface of the joint portion 2d, and the concave portions 2f are formed by joining the spherical bodies. 2f is formed. In particular, the spherical body contains silicon. Specifically, the spherical body is preferably at least one of silicon, silicon carbide, silicon nitride, silicon carbonitride, silicon oxide, and sialon. Identification can be done using line diffraction or transmission electron microscopy.

  In addition, the hole shape and the granular material have arbitrary cross-sections. For example, in the case of a hole shape, the width along the bonding portion 2d is 10 μm or more and 200 μm or less, and the depth is 10 μm or more and 200 μm or less. The width along the part 2d is preferably 10 μm or more and 48 μm or less, and the height is preferably 16 μm or more and 52 μm or less. If it is such a range, the surface area of 2 d of junction parts can be increased, without impairing the flow of a medium. In other words, the heat radiation characteristics of the heat sink 13 can be further improved because the same effect as that of the fin 2 can be obtained by the joint portion 2d having a further increased heat radiating surface area.

The width and depth of such a hole shape and the width and height of the granular material can be determined using an optical microscope and a magnification of 100 to 500 times. In addition, the convex part may be one in which a plurality of granules are integrated and joined to the joint 2d.

  FIG. 7 is an enlarged sectional view showing still another example of the heat sink D-D ′ of the example shown in FIG. 5. In FIG. 7, the hatching is shown differently in order to clearly show the concave portion 2 a and the convex portion 2 b.

  As shown in FIG. 7, the bonding portion 2 d preferably has an inclined surface 2 g that is inclined in the direction in which the heat generating member is placed. Thereby, for example, when the medium is flowed in the X direction shown in FIG. 1 for the purpose of heat exchange, the medium can be controlled to flow toward the base 1 on which the heat generating member is placed. Since the heat exchange efficiency with the substrate 1 is improved, the heat exchange efficiency of the heat sink can be further improved.

  Note that, as described above, when the medium is caused to flow in the X direction shown in FIG. 1 for the purpose of heat exchange, the joining portions 2d are arranged at equal intervals in FIG. Even if the junction 2d is provided on the other end side in the X direction and the inclined surface 2g is provided, the medium does not easily flow to the base 1 side, and it is difficult to improve the heat exchange efficiency, so that the medium enters the junction 2d. It is preferable to arrange many on the direction side (one end side in the X direction). Thereby, the medium can be efficiently flowed toward the base 1 on which the heat generating member is placed, and the heat exchange efficiency can be further improved.

  The fins 2 constituting the heat sink of the present embodiment are made of, for example, diamond, aluminum, copper, expanded graphite, glass, resin, or ceramics, and are particularly preferably made of ceramics.

  Here, as the ceramic material, alumina, zirconia, silicon nitride, aluminum nitride, silicon carbide, boron carbide, boron nitride, cordierite, or a composite thereof can be used.

In particular, when the heat generating member is a light emitting diode (LED) element for optical communication made of gallium-aluminum-arsenic (GaAlAs) or indium-gallium-arsenic-phosphorus (InGaAsP), the linear expansion coefficient of these compounds is Since it is about 5 × 10 ⁻⁶ / K and is close to the linear expansion coefficient of ceramics, even if a light emitting diode (LED) element is mounted on a heat sink, distortion due to heat generation is less likely to occur in the light emitting diode (LED) element. Cracks are less likely to occur at the junction between the heat sink and the light emitting diode (LED) element.

Further, when the fin 2 is made of ceramic, it is preferable to use silicon carbide, aluminum nitride, boron nitride, or a carbon fiber reinforced carbon composite material. Since silicon carbide, aluminum nitride, and boron nitride have a linear expansion coefficient of 3.7 × 10 ⁻⁶ / K or more and 6 × 10 ⁻⁶ / K or less, it depends on the linear expansion coefficient of the compound constituting the light emitting diode (LED) element. As a result, distortion and cracks due to heat generation are further less likely to occur.

The carbon fiber reinforced carbon composite material impregnates carbon fiber with a liquid for impregnation obtained by dispersing or dissolving powdered carbon, fine carbon fiber having a hollow inside, and a thermosetting resin in a medium. After that, the composite is obtained by molding, curing and firing so that the carbon fibers are arranged in one direction, and the coefficient of thermal expansion in the direction in which the carbon fibers are arranged is 3.7 × 10 ⁻⁶ /
K or more and 6 × 10 ⁻⁶ / K or less can be set.

  Furthermore, in order to improve the heat dissipation characteristics, it is preferable to include at least one of particles and fibers having higher thermal conductivity than the material forming the fin 2 described above. Carbon fiber is particularly preferred.

  In addition, it is preferable that the base | substrate 1 which comprises the heat sink of this embodiment is formed with the same material as the material which comprises the fin 2. FIG.

  1A shows a fin having a rectangular cross section perpendicular to the Z direction. However, when the fin 2 has a columnar shape, such as a circular shape, an elliptical shape, a polygonal shape, or a star shape. Any shape can be used as long as it has no problem in strength.

  FIG. 8 is a schematic cross-sectional view showing an example of an electronic component device in which an electronic component is mounted on the heat sink of the present embodiment.

  The electronic component device 20 of the example shown in FIG. 8 includes an electronic component 3, a circuit member 4 on which the electronic component 3 is mounted, and an electrically insulating support substrate 5 that supports the circuit member 4 on one main surface (front surface) side. A housing (package) 6 that houses the electronic component 3 and the circuit member 4 and heat sinks 10, 11, 12, 13, and 14 disposed on the other main surface (back surface) side of the support substrate 5 are provided. The circuit members 4 are arranged in two rows, for example, and are joined to the support substrate 5 by a brazing material.

  In the electronic component device 20 of the present embodiment, the electronic component 3 is mounted on the heat sinks 10, 11, 12, 13, and 14 having high heat dissipation characteristics of the present embodiment. As a result, by efficiently dissipating the heat generated from the electronic component 3, it is possible to suppress the electronic component 3 from becoming high heat, and the life of the electronic component 3 can be extended, so that the reliability can be improved.

  In particular, the electronic component device 20 is useful as a device that generates high heat during operation, such as a semiconductor module such as a PCU, a semiconductor device of a high-power LED headlamp, a DC high-voltage power supply device, and a switching device.

  Next, an example of the manufacturing method of the heat sink of this embodiment is demonstrated.

When obtaining a heat sink made of silicon carbide, first, the average particle size (D ₅₀ ) is 0.5 μm.
Boron carbide powder and lignin carboxylate powder are added to silicon carbide powder having a particle size of 2 μm or less, and mixed and pulverized by a ball mill, rotary mill, vibration mill, bead mill or the like to obtain a mixed powder.

Here, the content of each of the boron carbide powder and the lignin carboxylate powder is, for example, from 0.12% by mass to 1.4% by mass and from 1% by mass to 3.4% with respect to 100% by mass of the silicon carbide powder.
It is preferable to set it as mass% or less.

  And this mixed powder is mixed in an organic solvent with a binder, a dispersing agent, a plasticizer, a lubricant, etc., and a slurry is obtained.

  As the organic solvent, it is preferable to use at least one of toluene, ethanol, methanol, methyl ethyl ketone, trichloroethylene, and methyl isobutyl ketone.

  The binders include polyethylene glycol, methyl cellulose, polyethylene glycol, polyvinyl alcohol, polyvinyl butyral, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, styrene, vinyl chloride and acetic acid. It is preferable to use at least one of vinyl, and it is particularly preferable to use polyvinyl butyral or isobutyl methacrylate.

Moreover, it is preferable that the addition amount of a binder shall be 4 mass% 8 mass% or less with respect to 100 mass% of mixed powder. The amount of binder added is 4 to 8% by mass with respect to 100% by mass of the mixed powder.
If it is below, the strength and flexibility of the molded body are good, and the binder can be easily degreased.

Also, when obtaining a heat sink made of aluminum nitride, first, the specific surface area by gas adsorption BET method is 2.0 m ² / g or more and 3.0 m ² / g or less, and the uniaxial pressure molding density under a pressure of 50 MPa is 1.65. g / cm ³ or more 1.80 g / cm ³ or less, an average particle diameter _{(D 50),} for example, the 2μm or less of the aluminum nitride powder or 1 [mu] m, an alkaline earth metal oxide powder and the rare earth element oxide powder And mixed and pulverized in a ball mill, rotary mill, vibration mill, bead mill or the like to obtain a mixed powder.

Here, the total content of the alkaline earth metal oxide powder and the rare earth element oxide powder is preferably 1% by mass or more and 10% by mass or less with respect to 100% by mass of the aluminum nitride powder. .

  And a slurry is obtained by the same method as the case where the heat sink which consists of silicon carbide mentioned above is obtained.

  Next, using these slurries, a ceramic green sheet is formed by a doctor blade method, which is a general method of forming ceramics, and formed into a predetermined shape by punching with a mold or cutting with a laser beam.

  FIG. 9 is a plan view of a ceramic green sheet serving as a fin constituting the heat sink of the present embodiment.

  As shown in FIG. 9, after the ceramic green sheets 30 are laminated and fired, the portion that becomes the fin 2 of the heat sink is formed with an opening 31 so as to be a plurality of columnar fins arranged at intervals. It is. In other words, the opening 31 is between the adjacent fins 2 (space).

When the base body 1 and the fins 2 are formed of a laminated body having a plurality of plate-like bodies, the ceramic green sheets 30 to be the fins 2 out of the plurality of ceramic green sheets 30 manufactured as described above are combined with the base body 1. The ceramic green sheets are laminated, and the positions thereof are adjusted and laminated so as to have at least one of the concave portion 2a and the convex portion 2b in a portion facing the adjacent fins 2. It should be noted that the same binder as that used when the ceramic green sheet 30 was manufactured was previously applied to the bonding surfaces of the ceramic green sheets 30 as an adhesion liquid, laminated, and then passed through a flat plate-like pressing tool. Then, a pressure of about 0.5 MPa is applied, and then dried at about 50 to 70 ° C. for about 10 to 15 hours.

  In addition, in order to round the corner 2c formed by the convex portion 2b as shown in FIG. 4, the die used for processing the ceramic green sheet into a predetermined shape is rounded at the end of the punch. As a mold with a round shape, it is formed by pressing against the ceramic green sheet, or by adjusting the output and focus position of the laser beam, the processed end of the ceramic green sheet 30 has a rounded shape It can be obtained by laminating these ceramic green sheets 30.

  10A and 10B show another example of the ceramic green sheet that constitutes the joint of FIG. 5 that constitutes the heat sink of the present embodiment. FIG. 10A is a plan view, and FIG. 10B is an E diagram of FIG. It is sectional drawing in the -E 'line.

  As shown in FIG. 10B, the ceramic green sheet 32 provided with a curved portion 33 that is curved in advance and the opening 31 having a predetermined shape so as to form a plurality of columnar fins with an interval as shown in FIG. By laminating the processed ceramic green sheets 30, that is, by laminating the openings 31 and the curved portions 33 so as to coincide with each other, a curved joint 2 d as shown in FIG. 5 can be provided. In addition, as a method of curving the ceramic green sheet, for example, two curved jigs having a curved surface are prepared, and the ceramic green sheet 32 is sandwiched to provide the curved portion 33 in the ceramic green sheet 32. Moreover, you may process into a predetermined shape except the location which curved only the location where the junction part 2d is needed, and provided the curved location 33 beforehand.

  Further, in order to provide the concave portion 2e and the convex portion 2f on the surface of the joint portion 2d, a hole is made in advance in the portion that becomes the curved portion 33 in FIG. 10, or a large number of granular materials such as granules containing silicon or bed powder. Can be placed. For example, there are laser beam, machining, blasting, etc., but there are two jigs with protrusions and sandwiching the ceramic green sheet 32. The hole shape can be provided in the sheet | seat 32, and the part used as the recessed 2e can be obtained. Moreover, the method of mounting the granular material used as the convex 2f may sprinkle using a sieve etc., or may add a solvent etc. to a granular material to make a slurry, and may apply | coat using a brush, a roller, etc. The powder constituting the granular material used here is, for example, silicon carbide or silicon carbonitride powder, graphite powder and boron carbide (B4C) powder as additive components, silicon powder, silicon nitride And / or a powder of silicon oxide, a powder of sialon, a powder of at least one of magnesium oxide (MgO) and calcium oxide (CaO) as additive components, and an oxide of a rare earth element. Here, the granules placed on the curved portion 33 of the ceramic green sheet 32 are, for example, the above powder mixed and pulverized into a slurry, and dried with a spray dryer. For example, the sintered body fired and pulverized.

  11A and 11B show another example of the ceramic green sheet that constitutes the joining portion of FIG. 5 that constitutes the heat sink of the present embodiment. FIG. 11A is a plan view, and FIG. 11B is an E diagram of FIG. It is sectional drawing in the -E 'line.

  In order for the joint 2d as shown in FIG. 7 to have the inclined surface 2g inclined in the direction in which the heat generating member is placed, the inclined portion 35a as shown in FIG. 11 is provided. A ceramic green sheet 34 having a curved portion 35 and an opening 36 may be used. By laminating the ceramic green sheet 30 as shown in FIG. 9 and the ceramic green sheet 34 as shown in FIG. 11, the joining portion 2d having the fin 2 and the inclined surface 2g of the heat sink 14 shown in FIG. Can be produced. The inclined portion 35a is formed by applying an opening 36 to the curved ceramic green sheet in the same manner as the ceramic green sheet in FIG. 9, and then cutting the end of the opening 36 by laser machining, blasting, or machining. The inclined portion 35a may be provided by processing.

  The ceramic green sheet may be heated in a nitrogen atmosphere for 10 to 40 hours, held at 450 to 650 ° C. for 2 to 10 hours, and then naturally cooled and degreased as necessary.

  When the ceramic green sheet is made of silicon carbide, for example, in an inert gas atmosphere or in a vacuum atmosphere, the temperature is maintained at 1800-2200 ° C for 10 minutes to 10 hours, and then 2200-2350 ° C. By holding for 10 minutes to 20 hours in the temperature range, a ceramic sintered body having a relative density of 90% or more can be obtained.

The inert gas is not particularly limited, but it is preferable to use argon or helium because boron carbide decomposes when kept at 2000 ° C. or higher.

  When the ceramic green sheet is made of aluminum nitride, for example, in a nitrogen atmosphere or a mixed atmosphere of nitrogen and hydrogen, the firing temperature is maintained in the range of 1500 to 1900 ° C. for 5 to 20 hours. A ceramic sintered body having a density of 90% or more can be obtained.

  Further, the firing temperature and time may be appropriately set according to the thickness and volume of the ceramic green sheet laminate.

  Further, when the joint portion 2d is provided like the heat sinks 13 and 14, deformation of the fin 2 at the time of firing can be suppressed, and contact between the adjacent fins due to deformation can be prevented. The yield can be improved.

  By removing the outer side of the ceramic sintered body obtained by the above-described method by grinding or the like, a heat sink as shown in FIGS.

In the above description, the case where the ceramic green sheet is formed using the doctor blade method is shown. However, in order to obtain the heat sink made of silicon carbide, the ceramic green sheet is formed using the dry pressure forming method or the powder rolling method. In the case of conducting, first, water, a dispersant, boron carbide powder, silicon carbide powder having an average particle diameter (D ₅₀ ) of 0.5 μm or more and 2 μm or less,
Add lignin carboxylate powder, mix and grind in a ball mill, rotary mill, vibration mill, bead mill, etc. to make a slurry. In this slurry, celluloses such as methylcellulose and carboxymethylcellulose and modified products thereof, sugars, starches, dextrins and various modified products thereof, various water-soluble synthetic resins such as polyvinyl alcohol, synthetic resin emulsions such as vinyl acetate, lignin sulfonic acid Soda, gum arabic, casein, alginate, glucomannan, glycerin, sorbitan fatty acid ester and the like may be added and mixed, and then spray dried.

Here, the content of each of the boron carbide powder and the lignin carboxylate powder is, for example, 0.12% by mass to 1.4% by mass and 1% by mass to 3.4% by mass with respect to 100% by mass of the silicon carbide powder. It is preferable to do.

  In addition, before spray drying, coarse impurities and dust are removed by passing through a sieve having a particle size number of 200 described in ASTM E11-61 or a mesh finer than this mesh, and further using a magnetic force. It is preferable to remove iron and its compound by a method such as removing iron with an iron machine.

  The obtained ceramic granules can be formed into a ceramic green sheet having a relative density of 45% or more and 70% or less by molding using a dry pressure molding method or a powder rolling method.

  And after making into a predetermined shape using the punching process by a metal mold | die, or the cutting process by a laser beam, a heat sink can be obtained with the same method as the manufacturing method mentioned above.

  In addition, the heat sink obtained by the above-described manufacturing method is bonded to the back surface of the support substrate 5 on which the electronic component 3 is mounted via the circuit member 4 by using a bonding agent such as silicon grease. The component device 20 can be used.

DESCRIPTION OF SYMBOLS 1: Base | substrate 2: Fin 2a: Concave part 2b: Convex part 2c: Corner | angular part 2d: Joint part 2e: Concave part 2f: Convex part 2g: Inclined surface 3: Electronic component 4: Circuit member 5: Support substrate 6 : Housing (package)
10, 11, 12, 13, 14: heat sink
20: Electronic component equipment

Claims (9)

  A base on which the heat generating member is placed, and a columnar fin that is bonded to a surface of the base opposite to the surface on which the heat generating member is placed, and a plurality of which are arranged at intervals. Has at least one of a concave portion and a convex portion at a portion facing the adjacent fins.   The heat sink according to claim 1, wherein the fin is a laminated body including a plurality of plate-like bodies.   3. The heat sink according to claim 2, wherein at least one of the concave portion and the convex portion is provided from one end to the other end in a direction perpendicular to a height direction of the columnar fin.   The said fin has the said convex part in the site | part facing the said adjacent fin, and the corner | angular part formed by this convex part is rounded. A heat sink according to any one of the above.   The part of said adjacent fins is connected via the junction part, and this junction part is curving in the height direction of a fin between the said adjacent fins. 5. The heat sink according to any one of 4 above.   The heat sink according to claim 5, wherein the joint portion has at least one of a concave and a convex on a surface.   The heat sink according to claim 5, wherein the joint portion has an inclined surface that is inclined in a direction in which the heat generating member is placed.   The heat sink according to claim 1, wherein the fin is made of ceramics.   An electronic component device comprising an electronic component mounted on the heat sink according to any one of claims 1 to 8.

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